我正在尝试覆盖实体框架的SaveChanges()
方法以保存审核信息。我从以下开始:
public override int SaveChanges()
{
ChangeTracker.DetectChanges();
ObjectContext ctx = ((IObjectContextAdapter)this).ObjectContext;
List<ObjectStateEntry> objectStateEntryList = ctx.ObjectStateManager.GetObjectStateEntries(
EntityState.Added
| EntityState.Modified
| EntityState.Deleted).ToList();
foreach (ObjectStateEntry entry in objectStateEntryList)
{
if (!entry.IsRelationship)
{
//Code that checks and records which entity (table) is being worked with
...
foreach (string propertyName in entry.GetModifiedProperties())
{
DbDataRecord original = entry.OriginalValues;
string oldValue = original.GetValue(original.GetOrdinal(propertyName)).ToString();
CurrentValueRecord current = entry.CurrentValues;
string newValue = current.GetValue(current.GetOrdinal(propertyName)).ToString();
if (oldValue != newValue)
{
AuditEntityField field = new AuditEntityField
{
FieldName = propertyName,
OldValue = oldValue,
NewValue = newValue,
Timestamp = auditEntity.Timestamp
};
auditEntity.AuditEntityField.Add(field);
}
}
}
}
}
我遇到的问题是我在entry.OriginalValues
和entry.CurrentValues
中获得的值始终是新的更新值:
答案 0 :(得分:1)
已发现问题:
public ActionResult Edit(Branch branch)
{
if (ModelState.IsValid)
{
db.Entry(branch).State = EntityState.Modified;
db.SaveChanges();
return RedirectToAction("Index");
}
return View(branch);
}
以上述方式保存更新似乎会导致ChangeTracker
无法获取旧值。我通过简单地使用ViewModels来解决所有必需的更新:
public ActionResult Edit(BranchViewModel model)
{
if (ModelState.IsValid)
{
Branch branch = db.Branch.Find(model.BranchId);
if (branch.BranchName != model.BranchName)
{
branch.BranchName = model.BranchName;
db.SaveChanges();
}
return RedirectToAction("Index");
}
return View(model);
}
答案 1 :(得分:0)
要从数据库中获取旧值的副本而不更新EF实体,您可以使用
2018-05-03T13:57:15-04:00
或
context.Entry(yourEntity).GetDatabaseValues().ToObject()
警告:这确实会引发数据库调用。
答案 2 :(得分:0)
对我来说最简单的方法是:
var cadastralAreaDb = await _context.CadastralAreas.FindAsync(id).ConfigureAwait(false);
var audit = new Audit
{
CreatedBy = "Edi"
};
_context.Entry(cadastralAreaDb).CurrentValues.SetValues(cadastralArea);
await _context.SaveChangesAsync(audit).ConfigureAwait(false);
这已在ASP NET Core 3.1中进行了测试